President Trump met with the secretary general of NATO today at the White House. On the campaign trail, Trump questioned the modern-day relevance of the military alliance between Western powers. After all, it formed almost 70 years ago in response to the growing strength of the Soviet Union.

But today, we heard a different tone. President Trump spoke about a strong commitment to NATO and a new chill in U.S. relations with Russia. NPR's Scott Horsley joins us from the White House for more on this. And Scott, as we mentioned, on the campaign trail, President Trump often sounded like a NATO skeptic. What's changed?

SCOTT HORSLEY, BYLINE: Well, part of it is that chill in U.S.-Russia relations, especially after last week's chemical weapons attack by Russia's ally Syria and the retaliatory strike by the United States. But Trump also says NATO has changed and that the alliance is now more focused on battling terrorism, which this president considers America's No. 1 threat.

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PRESIDENT DONALD TRUMP: I complained about that a long time ago, and they made a change. And now they do fight terrorism. I said it was obsolete. It's no longer obsolete.

HORSLEY: Now, battling terrorism is not exactly new for NATO. In fact, the first time the alliance ever invoked its mutual defense pact was in response to the September 11 attacks. But NATO's secretary general, Jens Stoltenberg, does say the alliance can do more to fight terror, and they'll talk about that at a summit in Brussels next month, which will be President Trump's first overseas trip.

CORNISH: The president has also criticized NATO members for not spending enough money on their own defense, essentially arguing that they're leaving the U.S. to pick up the slack. Has that changed?

HORSLEY: This is still a persistent complaint for the president. He raises it just about every chance he gets. NATO members agreed several years ago to boost their defense spending to 2 percent of their respective economies by 2024. Right now, only five of the alliance members meet that target. But Stoltenberg says the number is growing.

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JENS STOLTENBERG: So they have started to move in the right direction. It's not enough. We still have a long way to go. But at least they have turned a corner. European allies have turned a corner. Instead of reducing defense spending, they have started to increase defense spending.

HORSLEY: Now, for comparison, the United States spends something over 3 percent of GDP on defense.

CORNISH: White House officials say Trump's support for NATO has been reinforced by Russia's actions. Does the president think Russia had advance warning of Syria's chemical weapons attack last week?

HORSLEY: The president was asked about that and said it's possible Russia was not aware but not likely. The U.S. intelligence community has not reached any kind of consensus on that, but we do know Russian military personnel were on that Syrian air base from which the chemical weapons attack was launched. And U.S. officials have said it would be hard for Russia not to have known. That is certainly coloring U.S. relations with Moscow. And remember; Trump wanted to work more closely with Vladimir Putin in battling ISIS. He spoke about that downturn today.

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TRUMP: Right now we're not getting along with Russia at all. We may be at an all-time low in terms of relationship with Russia. This has built for a long period of time. But we're going to see what happens.

CORNISH: Finally, the president also spoke last night with Chinese President Xi Jinping following up on their meeting last weekend. How did that go?

HORSLEY: Trump had a lot of kind words for President Xi today. He said he thinks the Chinese leader wants to help the U.S. in diffusing North Korea's nuclear program. Separately, the president gave an interview to The Wall Street Journal today in which he said the United States will not be labeling China a currency manipulator, backtracking on something he had often promised during the presidential campaign.

Now, Trump was asked if that was a quid pro quo for Chinese cooperation on North Korea, and he would not say. What is true is that China has not been artificially depressing its currency for some time now, so Trump's change in position is really just catching up with economic reality.